People

Current group members

Dr Lewis Alcott
I'm a biogeochemist interested in answering multidisciplinary questions associated with Earth surface processes and events including past, present and future environmental change.

Dr Casey Bryce

I am a geomicrobiologist specializing in microbes that use iron as an energy source. I combine approaches from geochemistry, microbiology and molecular biology to understand how these microbes influence the biogeochemistry of sediments, soils, peatlands, and ancient oceans.

Dr Heather Buss, Research Group Leader

My expertise is in low-temperature geochemistry and geomicrobiology and my research focuses on chemical weathering and mineral nutrient cycling in Earth’s Critical Zone.

Dr James Byrne

My research explores the links between magnetism and microbial processes in the environment supported by my multidisciplinary background in physics, geomicrobiology and environmental mineralogy.

Dr Erica Hendy

Dr Michael Henehan

My research centres on the global carbon cycle: from quantifying sources and sinks today, to understanding how climate interacted with these sources and sinks in the past, to documenting how all this was manifested in past atmospheric CO2 levels and temperatures. I apply a range of methods spanning metal(loid) isotopes in marine sediments and modern critical zone settings, to micropalaeontological methods in the fossil record. I have worked a lot in developing isotopic and trace metal proxies for ocean chemistry, atmospheric CO2 and temperature in foraminifera, and am increasingly exploring the potential for siliceous fossils to provide similar archives further back in time. This proxy development work involves live cultures of foraminifera and radiolarians, and calibration using modern sediments and plankton samples. I’m particularly interested in applying these climate and carbon cycle proxies to the greenhouse worlds of the Cretaceous and early Cenozoic – periods of high pCO2 and temperature that provide useful lessons for our potential future Earth.

Dr David Naafs

I’m an organic biogeochemist at the Organic Geochemistry Unit, specialising in using organic geochemical techniques to investigate climatic and biogeochemical processes in ancient and modern environments. My interdisciplinary research is driven by my desire and curiosity to understand the natural processes and mechanisms that influence Life and operate in Earth’s climate system. My approach is based on the rigorous application of state-of-the-art isotopic and organic mass spectrometry to study lipids and molecular fossils (biomarkers) derived from organisms across the three Domains of life, accumulated in modern and ancient natural archives from both the marine and terrestrial realm. By using climatological and biogeochemical information recorded in the lipids of organisms and preserved in the geological record I aim to answer long-standing questions related to the processes and mechanisms that drive changes in climate and biogeochemistry.

Professor Rich Pancost

My expertise is in organic geochemistry and I am co-lead of Bristol's Organic Geochemistry Unit. We can use the organic matter in soils, sediments, rocks and water to investigate a vast range of modern and ancient processes - and I do! But I am particularly interested in using biomarkers and their carbon and hydrogen isotopes to reconstruct past climate and biogeochemical processes across all timescales.

Dr Katherine Rothwell

I am an environmental mineralogist and soil chemist interested in redox processes and mineral transformation in soils, sediments, and groundwater.

Professor Laura Robinson
Drawing on samples collected through field work, ocean exploration and geochemistry, my research team is looking at the interactions between oceans and climate in the modern and the past. We apply a diverse range of geochemical analyses to deep sea corals including uranium series, radiocarbon and trace metal approaches. The data reveal unique insights into the links between deep ocean biogeochemistry and global climate, as well as the vulnerability of deep-sea ecosystems in a changing world.

Professor Fiona Whitaker
My research team works on interactions between groundwater biogeochemistry, hydrogeology and water-rock interactions, with a particular focus on carbonate systems. We couple fieldwork with process-based modelling, including fluid flow, geochemical and reactive transport modelling, to quantify key processes and evaluate fundamental controls. We study systems ranging from freshwater tufa and lake sediments to marine and evaporitic systems, using what we learn from modern systems to interpret the rock record and help manage aquifers and reservoirs.

Current Fellows

Dr Caitlyn Witkowski
I investigate the co-evolution of life and Earth, especially how climate, the carbon cycle, ecology, and depositional environments impact one another over geologic time using organic geochemistry and stable isotopes. My current focus is on Palaeozoic mass extinction events, looking for similarities that lead to radical and catastrophic moments in Earth history, relevant for our rapidly changing planet today.

Current postdoctoral researchers

Dr Markus Adloff
I use numerical Earth system models to understand the links between climate and biogeochemical cycles, and how signals of environmental change get preserved in geologic archives.

Dr Lena Chen
I am a geochemist interested in how minerals control the fate of trace metals and nuclear waste in the environment.

Dr Simon Cheung
I am a microbial ecologist specialized in using molecular and bioinformatics techniques to examine the dynamics, determinants and roles of microbial communities in natural and host-associated environments.

Dr Jagannath Biswakarma
My research mainly couples environmental and geochemical observations to understand how minerals and contaminants cycle across different ecosystems under dynamic conditions.

Toby Halamka
I am a geomicrobiologist and organic geochemist who studies the relationship between microbial physiology and lipid biomarker distributions.

Dr Md Hanif

Dr Stefanie Hetz
I am an ecological microbiologist with a particular interest in soil microbiology and geomicrobiology.

Dr Allana Queiroz de Azevedo
I am a Postdoc with expertise in benthic and planktonic foraminifera from Miocene and Quaternary focused in paleoceanography and paleoclimate changes. I also investigate the Southern African and South American Monsoon based on elementary and isotope geochemistry.

Dr Fin Ring-Hrubesh
I research the restoration of peatlands and associated changes in microbial cycling of elements. My work spans the fields of geochemistry and microbiology. In particular I am interested in the contribution of microbes to overall peatland function, whether restoration can revive a 'healthy' peatland microbiome and whether microbes can act as markers for restoration success

Dr Yiming Zhang
I am an isotopic organic geochemist with a special interest in carbon cycling and microorganisms in carbon-rich ecosystems, particularly peatlands and wetlands. I study the microbial dynamics and carbon fate of peatlands under past and present scenarios of drought, warming, and anthropogenic disturbance. I trace microbial metabolism activities through the carbon and hydrogen isotope compositions of microbial biomarkers, and explore the impact of microbial activities on carbon accumulation, greenhouse gas emissions, and dissolved organic carbon output in peatlands.

Zoe van Kemenade
I am a marine microbiologist and organic geochemist. My research involves the reconstruction of marine biogeochemical cycles, in particular the N and C cycle. I currently focus on carbon isotopic fractionation in 'ancient' algae.

Current postgraduate research students

Deicy Paola Alarcon Prado
Project title: Microbial responses to restoration of lowland agricultural peatlands
(Supervisor: Casey Bryce & Rich Pancost)

Sara Attfield
Project title: Combining Light and Bacteria to Design Cheap and Sustainable Methods of Uranium and Arsenic Removal from Drinking Water Sources
(Supervisor: James Byrne)

Amy Oakeshott
Project title: Peatlands Under Pressure: The Interplay of Natural and Anthropogenic Change on Microbiology and Emissions
(Supervisor: Casey Bryce)

Katie O'Neill
Project title: Magnetite Nanoparticles for Resource Recovery: From Metal Sorption to Water Treatment Solutions
(Supervisor: James Byrne)

Gowtham Sekar
Project title: Understanding the role of biological pump in the Cretaceous Oceanic Anoxic Events
(Supervisor: Michael Henehan & Rich Pancost)

Nea Sneddon-Jenkins
Project title: Understanding peatland microbial community responses to changing environmental conditions
(Supervisor: Casey Bryce)

Specialist Technicians

Harry Li-Kam-Tin

I am the research technician and lab manager for the Biogeochemistry Labs. Work in these labs spans across environmental mineralogy and microbiology, Harry helps facilitate this research and provide specialist assistance across a broad collection of techniques.

Sophie Litherland

I am the technician attached to the Radio mineralogy labs, working closely with lab users to ensure the safe working with radioactive isotopes. The work being carried out in the labs is to find long term disposal solutions for radioactive waste generated from Nuclear energy, primarily assisting in the development of a geological disposal facility

Honorary Staff

Dr Frances Cooper
I study the mechanics of large-scale continental deformation and the evolution of orogenic systems, including the Himalaya, the Andes, and the Western US Cordillera. Through an ongoing collaboration with the mining company, BHP, I have a particular interest in the tectonic controls on porphyry copper deposits.

Dr Kate Hendry
I am a biogeochemist and chemical oceanographer, interested in understanding nutrient cycling in the modern ocean, and the link between past climatic change, ocean circulation, nutrient supply and biological productivity.

Dr Tingjiang Peng

I am a Associate Professor from Lanzhou University, visiting Bristol for one year (Sept 2024-Sept 2025), based within the Schools of Earth Sciences and Chemistry collaborating with Dr Caitlyn Witkowski and Professor Rich Pancost. Our research focuses on untangling the complex and dynamic impacts of Tibetan uplift on depositional environments, climate, and biodiversity across the Cenozoic. During my stay, I shall use compound specific and stable isotope organic geochemistry to determine quantitative changes in temperature, ecology, and palaeoelevation in a north eastern Tibetan basin that spans the Oligocene to Miocene.